A teacher who had an affair with a married colleague sought revenge when it
ended by launching a campaign of harassment against him and his pregnant
wife, a court has heard.

Alison Goodchild, 31, was so furious when Dean Bull broke off their relationship that she graffitied his car and garage, sent takeaways to the house every other day, had catalogues delivered and arranged for an estate agent to value the property.

Insults daubed on the walls included: "Fat disrespectful b------" and "Fat ---- get out he don't love you".

The four-month ordeal only ended when Mr Bull, who teaches personal, social and heath education, took matters into his own hands, going undercover in a neighbour’s car with a video camera in a bid to catch the perpetrator.

A Vauxhall Corsa, later identified as Goodchild's, eventually came into view and was driven slowly up the street before a woman got out and began to spray the garage.

Mr Bull chased her but she managed to get away, Luton Magistrates Court heard. However, another neighbour noted down the vehicle’s registration plate and Goodchild was arrested.

When police arrived at her home in Luton last June, she attempted to covertly remove the battery and sim card from a Nokia phone found in her car, but was spotted by officers.

Barry Keech, chairman of the Magistrates, warned Goodchild, a science teacher, that she could face jail. He said she had been trying to get her own back on Mr Bull and had clearly not considered the effect her actions would have on his wife.

"This was a continued and persistent campaign of harassment against the victims which was clearly undertaken over a long period of time and did involve a lot of planning,” he added.

"It caused distress and considerable expense to the third parties by having to pay for takeaways and a lot of inconvenience with the estate agent turning up.”

Angela Kerner, defending, said: "They started an affair and it went on for quite some time. Promises were made by him to her which were broken. She believed she was being used and consequently took the steps you have heard. She accepts they were wrong."

Goodchild was due to stand trial on Monday but changed her plea to guilty last Thursday. She will now be assessed by the probation service.

Both parties worked at Ashcroft High School in Luton, Beds, at the time the offences took place, last year.

A council spokesman said: "We can confirm that there was a police investigation into a former member of staff at Ashcroft High about an incident that occurred while the person was still employed by the school.

"The person no longer works for the school, and as we don't comment on internal staffing issues, we do not wish to comment further."